The "creature" is a silicon-based being that was unearthed
in a Siberian mine. The woken creature infected a few of the miners and killed
the rest (each creature carries only 5 spikes used to infect hosts). Presumably
it evolved while most of the earth`s surface was still covered in molten lava
and looked nothing like it does now. This particular creature was created
by infecting a bipedal humanoid, most likely a neanderthal or cro-magnon,
and somehow it got trapped in the earth (quicksand, landslide...). Needing
no air to sustain itself, it entered a hibernative state and slumbered for
many millenia. Until now.

Astoundingly resilient and capable of regenerating the most
grievous cuts in mere minutes, it`s no wonder the AI was interested in the
creature the moment it intercepted a transmission by the miners to the neo-soviet
government. Governments are slowed down by bureaucracy, so Zetatech AVs were
on the site first. Quickly capturing the mature creature and recovering those
infected, it destroyed the rest, leaving only charred corpses for the soviets
to find.

The creature itself is only pseudo-intelligent, it can formulate
attack plans and figure out cause-effect relations (ie, when I turn the handle,
the door opens), not the hows or whys, nor does it care. Being only slightly
above animal intellect, it`s priority is to survive and multiply, and to be
the dominant species. Let`s just hope the PCs don`t let the creatures out
of the facility.

"The ovipositor":
The creatures breed by infecting other animals with a genetic virus
that rapidly (the process takes roughly 20 hours to complete) transforms
the victim into one of them. The tail contains five small hollow "spikes"
that the creatured use to convey the virus by stabbing the host with
the tail, and inserting the spike anywhere, just having the tip penetrate
the skin by 1mm is enough. When a spike is used, the next spike moves
in place from a sack in the tip of the tail. After being struck, the
victim instantly falls into a catatonic stupor, not reacting to any
stimuli. The process can be reversed by genetic treatment, but it must
be done within 12 hours of infection. After that the brain begins to
change. Also note that the changes that have already taken place before
the treatment are NOT reversed, they must be surgically corrected.

Regeneration:The creature regenerates wounds at an incredible rate,
1 point per 10 seconds, this means one can actually see the wounds knit
up before your very eyes! It will always regenerate to full health, until
you blast it to pieces or it loses too much tissue (suffers over 110 pts
of damage without feeding).